HMAC-SHA256 Generator

HMAC provides integrity/authenticity, not encryption. Requires a shared secret.
HMAC provides message authentication and integrity, not confidentiality.

About HMAC-SHA256

HMAC combines a cryptographic hash function with a secret key to verify message integrity and authenticity. Widely used in API signing and webhooks.

Security Notes

Keep keys secret and rotate as needed. Use hex/base64 consistently for transport. Avoid key reuse across domains.

HMAC-SHA256 generator online  free, no upload (FAQs)

FAQs

What does HMAC guarantee?
Integrity and authenticity (with a shared secret). Not confidentiality.
How to sign the correct bytes?
Define a canonical message format (ordering, encoding) and sign exactly those bytes.
Does this tool upload my data?
No. HMAC is computed locally in your browser.

HMAC-SHA256 signing FAQs

FAQs

What is HMAC?
A message authentication code combining a hash function and a secret key.
What is a good key length?
Use a 256-bit randomly generated key for strong security.